find byte ofsetts (decimal) in a catalogue that have non-utf8 bytes, for later viewing in a hex editor

catalog_nonutf8_finder.py

filename = "catalog.bad"
i = 0
with open(filename, 'rb') as f:
  while 1:
    byte_s = f.read(1)
    if not byte_s:
      break

    try:
      u = unicode(byte_s, "utf-8")
    except:
      print i

    i = i+1